1. Field the Invention
This invention relates to a locking structure of a connector with a waterproof packing to prevent incomplete locking of the connector.
2. Description of the Prior Art
FIG. 7 is a longitudinally cross-sectional view of a locking structure of a conventional waterproof connector which is disclosed Japanese Utility Model Laid-Open No. Showa 63-150479.
In this structure, a waterproof packing 18 made of rubber with two rows of sealing lips 19 and 20 is fixed to an inner wall 22 of a housing of a female connector part 21, and a male connector part 23 slidably contacts the two rows of sealing lips 19 and 20 when connected to the female connector part 21.
On an outer wall 24 of a housing of the male connector part 23 is disposed a resilient locking arm 25 to engage a locking projection 29 thereon with a locking hole 28 on an inner wall 26 of the female connector part 21 the instant the both connector parts 21 and 23 are completely locked. A female terminal 30 in the male connector part is engaged with a male terminal 31 in the female connector part 21.
However, with the construction described above, as indicated in FIG. 8 showing the relation between the stroke of the male connector half 23 with respect to the female connector half 21 and connector insertion force which is required to insert the male connector part 23 to the female connector part 21, the sum P3 of force required for causing the male connector half to proceed against the packing 18 and force T required for connecting both terminals with each other 30 and 31 is larger than load P1 applied to the locking arm 25 (load required to deflect the locking arm 25 when a front inclined face 29a of the locking projection 29 abuts a front end face 32 of the housing of the female connector part 21), which prevents an operator from sensing the engagement of the locking projection 29 with the locking hole 28 from a feeling thereof by of the hand. As a result, occasionally, the locking projection 29 is not engaged with the locking hole 28, resulting in incomplete connection of the connector parts 21 and 23. Although the load P1 may be increased by decreasing the inclined angle .theta. of the front face 29a of the locking projection 29, larger force is required to engage the both connector parts.